Microsoft Excel仍然是世界上最流行的电子表格应用程序。Excel电子表格数据通常很敏感，包含个人或财务数据。可以理解，您可能会考虑对Excel文件进行额外保护，例如密码。
您可以使用多个选项对任何Excel文件进行密码保护，包括集成的Excel密码工具或第三方Excel密码选项。
1. 使用集成工具密码保护 Excel 工作表(1. Password Protect An Excel Sheet Using Integrated Tool)
Excel密码保护的第一个选项是集成工具。整个Microsoft Office套件都有一个密码保护工具，可用于保护Excel电子表格、Word文档、PowerPoint演示文稿等。
在 Excel 中，前往File > Info. 选择Protect Workbook，然后从下拉菜单中选择Encrypt with Password 。
现在，为您的Excel(Excel)电子表格输入一个安全密码。确保您的密码强度高且唯一，按OK，然后重新输入密码进行确认。
下次您尝试打开Excel电子表格时，您会遇到密码输入表单。
Excel 新手？查看我们的Microsoft Excel 基础教程(Microsoft Excel basics tutorial)以快速掌握技巧！
Microsoft Office 密码保护的安全性如何？(How Secure Is Microsoft Office Password Protection?)
Microsoft Office 97-2003使用了一种非常糟糕的加密标准，称为RC4。旧的加密算法有许多漏洞，这使得破解旧Excel文档上的密码变得异常容易。
Microsoft Office 2007-2013看到了升级的加密算法，切换到更强大的 AES-128 算法。Office 2016-2019 使用 AES-256 加密算法，使用现有技术在合理的时间范围内是牢不可破的。
额外的 Excel 保护(Extra Excel Protections)
Microsoft Excel也有一些额外的安全功能：
- 标记为最终文件：(Mark as Final:)将文件标记为完成，通知电子表格的其他用户他们不应进行任何更改。但是，将电子表格标记为最终电子表格不会提供任何额外的密码保护。
- 保护当前工作表：当您对(Protect Current Sheet:)Excel工作表进行密码保护时，您可以为工作簿中的特定电子表格添加一个小的附加保护层。有权访问Excel文件的人仍然可以查看电子表格，但如果没有正确的密码，则无法进行任何更改。您也可以为此选项使用不同的密码。
- 限制访问：(Restrict Access:)大型组织可以使用一个选项来限制使用安全模板或其他标识符的某些个人的访问。
- 添加数字签名：(Add a Digital Signature:)数字签名选项验证文件在发件人和收件人之间保持未篡改，确保内容相同。
您可以结合使用附加安全功能以及Excel电子表格密码保护选项，尤其是在共享 Excel 电子表格时(especially if you’re sharing an Excel spreadsheet)。
2. 7-Zip
同时加密多个Excel(Excel)文件的一个好方法是使用免费的存档工具7-Zip对多个( 7-Zip)Excel文件进行密码保护。您可以使用 7-Zip 加密单个Excel文件的整个文件夹，密码保护整个Excel电子表格选择，而不是一次一个。
首先，下载并安装最新版本的7-Zip。安装后，前往包含Excel电子表格的文件夹。(Once)现在，将鼠标光标拖到要密码保护的文件上以将它们全部选中。或者，按住CTRL并左键单击以使用鼠标选择单个文件。
完成选择后，右键单击并选择7-Zip > Add to Archive以打开 7-Zip 存档选项。加密(Encryption )选项在右侧。输入一个强大且唯一的密码，然后按OK。
现在，您必须输入密码才能打开存档中的任何(inside)Excel电子表格。但是存档之外的电子表格不受密码保护。选择非密码保护的Excel电子表格（在存档之外）并删除它们。
3. Windows 加密文件系统(3. Windows Encrypting File System)
Windows 加密文件系统(Windows Encrypting File System)( EFS ) 是用于单个文件的Windows集成加密系统。EFS与用于全盘加密的Bitlocker不同。(Bitlocker)相反，EFS在逐个文件的基础上工作，非常适合用密码保护Excel电子表格。
要使用EFS加密您的文件，请右键单击Excel电子表格并选择Properties。现在，选择“高级”，然后选中“(Advanced, )加密内容以保护数据(Encrypt contents to secure data)”复选框。按OK，然后按应用。(Apply.)
将出现加密警告(Encryption Warning)。它解释说，在某些情况下加密单个文件可能会导致问题，并且加密整个文件夹可以提供更多保护。如果文件位于经常访问的文件夹中，则每次要访问任何其他文件时都必须解锁该文件夹。解决此问题的一种方法是将文本文件放在单独的文件夹中，并将其用作安全文件夹。
确认您的选择后，加密文件系统(Encrypting File System)将询问您是否要备份加密密钥。如果您忘记了解密密码，您可以使用加密密钥备份。
导出您的加密密钥备份(Exporting Your Encryption Key Backup)
如果您选择导出加密密钥备份以提高安全性，Microsoft 证书导出向导(Microsoft Certificate Export Wizard)将运行。该向导将指导您创建加密密钥并将其导出到外部媒体源，例如USB闪存驱动器。
从第一页中选择个人信息交换，然后选中(Personal Information Exchange)导出所有扩展属性(Export all extended properties)。在下一页上，您必须输入一个安全且唯一的密码( input a secure and unique password)来密码保护您的文件。将加密类型切换为AES256-SHA256（extremely strong encryption!），然后给您的加密密钥备份一个文件名。按完成(Finish)以完成该过程。
该过程完成后，您会在记事(Notepad)本文本文件图标上看到一个小锁图标，指示其加密状态。
4.AxCrypt
另一个用于密码保护Excel工作表的便捷工具是AxCrypt，它是一种方便但功能强大的加密工具。
下载并安装AxCrypt。第一次运行AxCrypt时，您必须完成设置。重要的是，您必须在注册过程中提供真实的电子邮件地址，否则您将不会收到免费的AxCrypt许可证。收到代码后，将其复制并粘贴到AxCrypt 中(AxCrypt)，然后再继续。
您还需要创建一个强大且唯一的AxCrypt密码。AxCrypt密码充当Excel电子(Excel)表格(AxCrypt)的加密和解密密钥。注意AxCrypt警告。恢复您的密码将只允许访问与文件关联的帐户。它不允许您解密使用旧密码保护的文件。
准备好后，将Excel(Excel)电子表格文件拖放到AxCrypt窗口中。如果您登录AxCrypt，它会自动加密您的文件。同样，如果您登录AxCrypt并尝试打开文件，它不会出现密码提示。如果您关闭AxCrypt（也会将您注销），当您尝试打开电子表格时，您将收到密码提示。
AxCrypt是一个免费的加密工具，这就是为什么它出现在我们的最佳 Windows 免费软件程序列表中( list of the best Windows freeware programs)。
密码保护 Excel 电子表格的最佳方法是什么？(What’s The Best Way To Password Protect An Excel Spreadsheet?)
在过去，使用Microsoft Office的集成密码保护对Excel文件或工作表进行密码保护是有风险的。加密算法不够强大，存在多个漏洞，导致无法使用。由于Microsoft Office现在使用AES-256，因此您可以放心，Excel电子表格上的密码保护是值得信赖的，并且无法使用当前技术破解。
由于集成密码保护一次只处理一个文件，您还可以考虑使用 7-Zip 加密选项。如果您正在处理要保护的大量Excel电子表格，则在一个存档中保护所有这些电子表格（使用强大且唯一的密码！）是一个方便的选项，它也使用AES-256。
想知道一个强大而独特的密码吗？查看这些创建您将永远记住的密码的( to create a password you’ll always remember)简单方法。
How to Securely Password Protect an Excel File
Microsoft Excel remаins the most popular spreadsheet application in the world. Excel spreadsheet data is оften sensitive, containing personal or financial data. Underѕtandably, you might consider addіtional protection fоr your Excel files, such as a рassword.
You can password protect any Excel file using several options, including the integrated Excel password tool or third-party Excel password options.
1. Password Protect An Excel Sheet Using Integrated Tool
The first option for Excel password protection is an integrated tool. The entire Microsoft Office suite has a password protection tool you can use to secure your Excel spreadsheets, Word documents, PowerPoint presentations, and so on.
In Excel, head to File > Info. Select Protect Workbook, then Encrypt with Password from the dropdown menu.
Now, enter a secure password for your Excel spreadsheet. Ensure your password is strong and unique, press OK, then re-enter your password to confirm.
Next time you attempt to open the Excel spreadsheet, you’ll meet the password entry form.
New to Excel? Check out our Microsoft Excel basics tutorial to learn the ropes – fast!
How Secure Is Microsoft Office Password Protection?
Microsoft Office 97-2003 used a very poor encryption standard, known as RC4. The older encryption algorithm has numerous vulnerabilities, which makes cracking the password on an older Excel document incredibly easy.
Microsoft Office 2007-2013 saw an upgraded encryption algorithm, switching to the much stronger AES-128 algorithm. Office 2016-2019 uses the AES-256 encryption algorithm, which is unbreakable within a reasonable timeframe using existing technology.
Extra Excel Protections
Microsoft Excel has a few extra security features, too:
- Mark as Final: Marks the file as complete, which informs other users of the spreadsheet that they should not make any changes. However, marking a spreadsheet as final does not provide any additional password protection.
- Protect Current Sheet: You can add a small additional layer of protection to a specific spreadsheet within your workbook when you password protect an Excel sheet. People with access to the Excel file can still see the spreadsheet but cannot make any changes without the correct password. You can use a different password for this option, too.
- Restrict Access: An option large organizations can use to restrict access to certain individuals using security templates or other identifiers.
- Add a Digital Signature: The digital signature option verifies that the file remains untampered between the sender and recipient, ensuring the content is the same.
You might use a combination of additional security features alongside the Excel spreadsheet password protection option, especially if you’re sharing an Excel spreadsheet.
2. 7-Zip
A great method for encrypting multiple Excel files at the same time is to use the free archive tool, 7-Zip to password protect multiple Excel files. You can use 7-Zip to encrypt a whole folder of individual Excel files, password protecting an entire selection of Excel spreadsheets rather than one at a time.
First, download and install the latest version of 7-Zip. Once installed, head to the folder containing your Excel spreadsheets. Now, drag your mouse cursor over the files you want to password protect to select them all. Alternatively, hold CTRL and left click to select individual files with your mouse.
After finalizing your selection, right-click and select 7-Zip > Add to Archive to open the 7-Zip archive options. Encryption options are on the right. Enter a strong and unique password, then press OK.
Now, you must enter a password before opening any of the Excel spreadsheets inside the archive. But the spreadsheets outside the archive are not password protected. Select the non-password protected Excel spreadsheets (outside the archive) and delete them.
3. Windows Encrypting File System
The Windows Encrypting File System (EFS) is Windows integrated encryption system for individual files. EFS is unlike Bitlocker, which you use for full disk encryption. Instead, EFS works on a file-by-file basis, perfect for password-protecting an Excel spreadsheet.
To use EFS to encrypt your file, right-click the Excel spreadsheet and select Properties. Now, select Advanced, then check the box to Encrypt contents to secure data. Press OK, then Apply.
The Encryption Warning will appear. It explains that encrypting a single file can cause an issue under certain circumstances and that encrypting the entire folder offers more protection. If the file is in a frequently accessed folder, you’ll have to unlock the folder each time you want to access any other file. One way around this is to place your text file in a separate folder and use this as your secure folder.
After confirming your selection, the Encrypting File System will ask you if you want to take a backup of the encryption key. You can use the encryption key backup if you forget your decryption password.
Exporting Your Encryption Key Backup
If you choose to export your encryption key backup for additional security, the Microsoft Certificate Export Wizard will run. The wizard will guide you through the creation and export of your encryption key to an external media source, such as a USB flash drive.
Select Personal Information Exchange from the first page, and check Export all extended properties. On the next page, you must input a secure and unique password to password protect your files. Switch the encryption type to AES256-SHA256 (extremely strong encryption!), then give your encryption key backup a filename. Press Finish to complete the process.
Once the process is complete, you’ll see a small lock icon on the Notepad text file icon, indicating its encryption status.
4. AxCrypt
Another handy tool for password protecting Excel sheets is AxCrypt, a handy yet powerful encryption tool.
Download and install AxCrypt. The first time you run AxCrypt, you’ll have to run through the setup. Importantly, you must provide a real email address during the sign-up process, or else you won’t receive your free AxCrypt license. After receiving the code, copy and paste it into AxCrypt before continuing.
You also need to create a strong and unique AxCrypt password. The AxCrypt password acts as the encryption and decryption key for your Excel spreadsheets. Take heed of the AxCrypt warning. Restoring your password will only allow access to the account associated with the files. It will not allow you to decrypt files secured with an old password.
When you’re ready, drag and drop an Excel spreadsheet file into the AxCrypt window. If you are signed into AxCrypt, it will encrypt your files automatically. Similarly, if you are logged into AxCrypt and attempt to open a file, it will not present a password prompt. If you close AxCrypt (which also logs you out), you will receive a password prompt when you attempt to open the spreadsheet.
AxCrypt is a free encryption tool, which is why it features in our list of the best Windows freeware programs.
What’s The Best Way To Password Protect An Excel Spreadsheet?
In the old days, using Microsoft Office’s integrated password protection to password protect an Excel file or sheet was risky. The encryption algorithm was not strong enough and had multiple vulnerabilities, rendering it unusable. As Microsoft Office now uses AES-256, you can rest assured that the password protection on your Excel spreadsheet is trustworthy and impossible to break using current technology.
As the integrated password protection only handles one file at a time, you might also consider the 7-Zip encryption option. If you are dealing with a large volume of Excel spreadsheets that you want to protect, password protecting all of them in a single archive (with a strong and unique password!) is a handy option that also uses AES-256.
Wondering about a strong and unique password? Check out these easy ways to create a password you’ll always remember.
